Functional Mineral Pigments
Functional mineral pigments are used in large quantities in paint, paper, plastics, rubber, textiles, agriculture, and several other industries. Originally extender pigments were employed only to lower cost. They were thought of merely as adulterants to replace more expensive prime pigments and binders. However, over the years their role has become better understood, and today […]
Crushing & Grinding of Gypsum
In the crushing and grinding of metallics for beneficiation, the sizing is normally done to liberate the metals or sulphides for further processing to improve recoveries of the basic metals or minerals. The objective is to reduce the ore in size through various closely controlled stages to that degree of fineness which gives an economic […]
Beneficiation of Kaolinite Clay from Silica Sand Washings
Silica sand has been mined in Illinois from the St. Peter Sandstone since the turn of the century, especially in the area around Ottawa on the Illinois River in the north-central part of the state. Production of this sand, consumed mainly by the glass and foundry industries but also sought after for many other uses, […]
Activated Bleaching Clay
Activated bleaching clays, so called because of their ability to remove color bodies from bleach fats and oils, are produced from clays of bentonitic origin. Activation is achieved by subjecting these clays to physical or chemical alteration to increase selective sorption capacities. Bentonitic clays which are suitable for production of activated bleaching clays contain the […]
Design Start-Up and Operation of the Hygas Pilot Plant
The HYGAS Process is one of several coal conversion processes now under development within the United States and is the most advanced in development. It is based on the overall reaction of coal and water to produce methane, which is the major constituent of natural gas,and a by-product, carbon dioxide, which is exhausted to the […]
Techniques to the Extraction of Values from Municipal Refuse
Incineration has, in recent years, been considered by many as a major source of air pollution. However, a number of reports refute this belief. The former report states that the National Academy of Sciences has published data showing that refuse combustion accounts nationally for only 2.6 percent of air pollutants. The report also states that […]
Gypsum Calcining
Gypsum is the crystalline chemical compound CaSO4ยท2H2O. A close chemical relation – and frequently occurring with Gypsum – is Anhydrite which is CaSO4. Gypsun has wide commercial use because relatively simple heat processing reduces it to Plaster of Paris. While Anhydrite can be converted to Gypsum and thence to Plaster of Paris, the procedure is […]
Metallurgical Grade Fluorspar Briquets – How Process
The Oglebay Norton Company has traditionally been a supplier of metallurgical grade fluorspar gravel to the American steel industry and, in the early sixties, fluorspar pellets were entered into the market. The gravel has been imported from Mexico, the pellets were produced by the Minerva Company in southern Illinois. Use of waterglass or tall oil […]
Phosphate Rock Beneficiation
Many new mines overseas have also become significant. This includes countries such as Senegal, Togo, Israel, Spanish Sahara, and Jordan. Limited production, often as by-products, has been noted in South Africa, Brazil, and other countries. In recent years, and even recent months, we have learned of many new areas being considered as potential sources of […]
Topaz Flotation
Samples of a topaz-bearing gneiss from Jefferson County, Colorado, and a topaz-bearing schist from Chesterfield County, South Carolina, were obtained for the investigation. These are the areas outlined by USGS as containing probable commercial quantities of topaz. Partial chemical analyses of the samples are shown in table 1. Mineralogical examination of the Colorado gneiss showed […]